Conventionally, there has been publicly known a technique in which a controller determines whether or not an automatic traveling machine operates erroneously by performing positioning with signals from GPS satellites, and confirming or checking a position of the automatic traveling machine in a specific area, and stops the automatic traveling machine in the case of erroneous operation (e.g., refer to Patent Document 1).
Moreover, there has been publicly known a technique in which in a work form in which straight traveling of traveling along a linear work route and traveling for route change of traveling in a set traveling pattern decided beforehand from a terminal portion of the linear work route toward a next linear work route are repeated by a combine harvester, the automatic route change is enabled so that trouble of the route change is eliminated and an operation burden of a driver is reduced, and further, voice notification means is provided to enable the driver to easily recognize that this route change is being automatically performed (e.g., refer to Patent Document 2).